All activities involved in the preparation of negatives, positives, half-tones, linework and solids in the preparation of metal plates is a photo-mechanical process. A metal printing plate is a photo contact print, exposed to light, developed and processed for the lithographic printing press.
No ghosting effect, influence, crossover influence, front-to-back color variation or across the sheet color variations are ever established by the making of a printing plate. Conventional printing presses equipped with conventional inkers introduce inherent ghosting effects and other inaccurate printing of the printing plate onto the printed sheet. It is the effect of a particular form or printed format with its ghosting potential, front and back influence, and crossover, which is transmitted to the conventional inking system and is continuously transmitted back and forth from the printing plate to the inking system and from the inking system back to the printing plate. This continues throughout the run, making color control very difficult and color variation the norm for conventional printing presses. Heretofore color variations have been established and perpetuated throughout a printing run by conventional inking systems.
Structural components of inking systems heretofore devised have been eliminated from the improved inking systems disclosed herein while providing a new structure capable of forming a smooth continuous film of ink on a resilient applicator roller surface for application to a printing plate to provide photo-mechanical reproduction of the printing plate onto a blanket cylinder and to the paper. No ink keys are employed and no job-to-job adjustments are necessary. To change from one job to another, one merely changes the printing plate. No inker adjustments are made to match the new job. Solids, half-tones, line work and process, all are printed at the same time and at the same ink setting. Gear streaks, hickeys, and improper water balance are problems which constantly plague printers using conventional inking systems.
The improved inking system disclosed herein offers a solution to the technical problem of providing an inking system which will faithfully reproduce an image on a printing plate by a photo-mechanical process while eliminating gear streaks, ghosting, and color variation resulting from the inability of the printing press to offer a fresh continuous uniform film on each revolution of the printing plate.